It is known that rechargeable batteries, such as a lithium-ion rechargeable battery and a lithium polymer rechargeable battery, will expand if discharging and charging are repeated. Then, in a battery accommodating device for accommodating such a battery, an expansion of the battery is predicted and a space for a battery chamber is secured in advance, thereby allowing an expansion of the battery.
Conventional technical documents relating to the present invention are listed below.    Patent Document 1: Japanese Unexamined Patent Application Publication No. 2005-159638    Patent Document 2: Japanese Unexamined Patent Application Publication No. 2002-232810